Computer graphics processing and selective visual display system – Display peripheral interface input device – Touch panel
Reexamination Certificate
2001-11-14
2003-04-22
Chow, Dennis-Doon (Department: 2675)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Touch panel
C345S174000, C178S018010, C178S018050
Reexamination Certificate
active
06552718
ABSTRACT:
This invention claims the benefit of priority to Korean Patent Application No. 2001-1245 filed Jan. 10, 2001 and Korean Patent Application No. 2001/8970 filed Feb. 22, 2001. The present invention relates to a contact of substrates of a touch panel, and more particularly, to a method of bonding the substrates in order to embody optimal design thereof by reducing an inactive area on the touch panel and a contact structure of a flexible printed cable (FPC) for applying external signals to the touch panel.
BACKGROUND AND PRIOR ART
A personal computer, a portable transmitter, a personal digital assistant and the like perform text and graphic processing by using various input devices such as keyboard, mouse and digitizer.
In particular, the digitizer is a device for digitally detecting positions of the fingers or pens on a specifically manufactured flat panel and outputting their values in the form of X/Y coordinates. The digitizer has an advantage that it can input characters or figures more conveniently and precisely than the mouse, keyboard, scanner and the like. Among the digitizer, a touch panel has frequently been used for an electronic note or the personal digital assistant (PDA).
As shown in
FIG. 1
, a digitizing apparatus, which can perform various functions of screen motions on a display
10
by attaching a touch panel
20
to a front surface of the display
10
, is a typical type of a graphic user interface (GUI). The touch panel can be divided into a resistive type, a capacitive type, an ultrasonic wave type, an optical (infrared) type, an electromagnetic induction type and the like, according to operating methods thereof. Such various touch panels have features that signal amplification, resolution, difficulty in design and manufacturing techniques, and the like can be varied according to the operating methods thereof. The operating method of the touch panel can be selected according to its durability, its economical efficiency, etc. in addition to its optical property, its electromagnetic property, its mechanical property, its environmental resistance, its input property, etc.
The resistive touch panel has been combined with a liquid crystal display (LCD) and widely spread as an input device for use in the electronic note, the PDA, the portable personal computer, etc. Its design is very advantageous as compared with the other types of the touch panels, in view of thinness, compactness, lightness, low power consumption, etc. There are matrix and analog methods as a detection method of the resistive touch panel. Further, 0.1~0.2 mm thick film substrate, 0.2~2.0 mm thick glass substrate and 1.0~2.0 mm thick plastic substrate can be used as a transparent electrode, and upper/lower electrodes are constructed by combining these substrates. The analog detection method is again divided into 4-wire type, 5-wire type, 8-wire type, etc. according to electrode wiring.
FIG. 2
is a schematic view of the resistive touch panel
20
. The resistive touch panel is constructed by fabricating transparent conductive films
50
on a first substrate
30
for forming the upper electrode and a second substrate
40
for forming the lower electrode, respectively, and then by fabricating dot spacers
60
for electric insulation between the first and second substrates
30
,
40
on the conductive film
50
of the second substrate
40
. In the resistive touch panel, distribution of the signals on X/Y coordinates by means of the two substrates is calculated and is in turn sent to external driver soft through a connector. Further, the touch panel is divided into the 4-wire, 5-wire, 8-wire types according to the number of bus lines for recognizing the signals on the X/Y coordinates of the substrates. Consequently, characteristics of a recognition or signal processing method of the signals distributed on the X/Y coordinates can be varied according to the number of the bus lines.
FIGS.
3
(
a
) and (
b
) show the 4-wire resistive touch panel
20
, in which an insulating layer is processed and placed between the first substrate
30
and the second substrate
40
.
As shown in FIG.
3
(
a
), in order to form an active area a
1
made of high resistive metal, X-axis potential compensating electrodes
60
a,
60
b
made of low resistive metal are arranged in two lines on both lateral sides of the transparent conductive film
50
of the second substrate
40
, after the insulator layer has been formed on the substrate. Further, dot spacers
60
made of insulating material for electric insulation between the two substrates, i.e., the first substrate
30
and the second substrate
40
, are formed within the active area a
1
defined by a space between the potential compensating electrodes
60
a,
60
b.
As shown in FIG.
3
(
b
), in order to form an active area a
2
made of high resistive metal, Y-axis potential compensating electrodes
70
a,
70
b
made of low resistive metal are arranged in two lines on both lateral sides of the transparent conductive film
50
of the first substrate
30
, after the insulator layer has been formed on the substrate.
Flexible printed cables (FPC)
80
for applying external signals to the touch panel
20
are connected to the first and second substrates
30
,
40
.
Before the first and second substrates
30
,
40
are bonded together to FPC contacts
81
formed thereon, an electrical signal path made of conductive material is formed in order to apply the electric signals to the first substrate
30
. After the FPCs
80
have been contacted to the FPC contacts
81
of both substrates, the second substrate
40
for sensing the X coordinate and the first substrate
30
for sensing the Y coordinate are bonded together in a state where the transparent conductive films
50
face each other. The X-axis and Y-axis potential compensating electrodes
60
a,
60
b;
70
a,
70
b,
which are formed, respectively, on the first substrate
30
and the second substrate
40
, are gathered on one side of the insulator layers
31
,
41
. Further, each of the first and second substrate
30
,
40
has a predetermined FPC contact
81
for bringing the substrates into contact with the FPC
80
.
The FPC contact
81
of the second substrate
40
comprises of a pattern that protrudes from the X-axis potential compensating electrode
60
a
by an arbitrary length (inactive area) L
1
; and another pattern that extends along an outer periphery of the active area a
1
, is then bent, and further extends from the other X-axis potential compensating electrode
60
b
disposed parallel to the pattern. When the two substrates
30
,
40
disposed parallel to each other are combined together by causing them to be disposed within the area having the arbitrary length L
1
formed by the FPC contacts
81
, it is constructed such that the other pattern, which abuts against the FPC contact
81
of the first substrate
30
, is also disposed in parallel. Therefore, the patterns of the second substrate
40
have configurations that they protrude from the insulator layer
41
to the outside by an arbitrary length.
The contact
81
of the first substrate
30
has a configuration that patterns, which are gathered from each end of the Y-axis potential compensating electrodes
70
a,
70
b
toward a central portion of the first substrate, protrude to the outside by an arbitrary length L
2
.
The contact points formed by respective FPC contacts
81
of the first substrate
30
and the second substrate
40
will be described according to the bonding process of the first substrate
30
and the second substrate
40
. When the first substrate
30
is put over and combined with the second substrate
40
, the pattern of the first substrate
30
comes exactly into contact with that of the second substrate
40
. Thus, the first and second substrates
30
,
40
can form the contact which the FPC
80
for applying the external signals via the FPC contact
81
gathered at one point can be contacted.
In order to detect the X coordinate in the aforementioned constitution, by applying a potential to the second substrate
40
through the FPC contact
81
Ahn Young-Soo
Oh Young-Jin
ATough Co., Ltd.
Chow Dennis-Doon
Law Offices of Brian S. Steinberger , P.A.
Steinberger Brian S.
LandOfFree
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